Originally Posted by dgs
A properly designed coil spring will have theoretical infinite life, if operated within its design parameters...
Originally Posted by Anders
...I does have an extra set of springs to Ruth, but they are exactly on the spot the same height as my old. ..
Let's hear what the spring experts say at Eaton Detroit Spring:
Theory isn't practical in the life of an automotive spring. Springs sag, ride hard and they break. They 'work harden' with extended use which causes them to ride hard. Springs are always replaced in pairs to be sure they both came from the same batch of steel and heat treat.
So, looking at heights only paints a partial picture. Springs can be worn out even though they look ok. If you want that new car ride, treat your car to new springs. - Dave